A battery is typically comprised of a number of individual cells that are connected in series to produce an overall battery voltage. Some battery types, such as nickel-cadmium or nickel-hydrogen, are rechargeable. When maintaining such a battery, several problems may occur that irreversibly damage the battery or reduce its performance or lifespan. To avoid these problems, it is advantageous to monitor the voltage across each battery cell when the battery is being recharged or discharged.